Summary

This phase I/II trial is studying the side effects and best dose of vorinostat when given together with rituximab and combination chemotherapy and to see how well it works in treating patients with newly diagnosed stage II, stage III, or stage IV diffuse large B-cell lymphoma. Vorinostat may stop the growth of cancer cells by blocking some of the enzymes needed for cell growth and by blocking blood flow to the cancer. Monoclonal antibodies, such as rituximab, can block cancer cell growth in different ways. Some block the ability of cancer cells to grow and spread. Others find cancer cells and help kill them or carry cell-killing substances to them. Drugs used in chemotherapy, such as cyclophosphamide, doxorubicin hydrochloride, vincristine, and prednisone, work in different ways to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing. Giving vorinostat together with rituximab and combination chemotherapy may kill more cancer cells

OUTLINE: This is a multicenter, phase I dose escalation study of vorinostat followed by a phase II study.

Patients receive oral vorinostat once daily on days 1-5 or 1-9 (according to dose level), rituximab IV, cyclophosphamide IV over 30-60 minutes, doxorubicin hydrochloride IV, and vincristine IV on day 3. Patients also receive oral prednisone once daily on days 3-7. Treatment repeats every 21 days for 8 courses in the absence of disease progression or unacceptable toxicity.

Paraffin block, core needle biopsy, and whole blood samples may be collected at baseline and during the first course of treatment for further analysis.

After completion of study treatment, patients are followed every 6 months for 2 years, and then annually for 3 years.